Aspirin and acetaminophen are both common medications used to reduce fever and relieve pain, but they have different mechanisms of action.Aspirin acetylsalicylic acid is a nonsteroidal anti-inflammatory drug NSAID that works by inhibiting the production of prostaglandins. Prostaglandins are hormone-like substances that play a role in inflammation, pain, and fever. Aspirin inhibits the enzyme cyclooxygenase COX , which is responsible for the synthesis of prostaglandins. There are two main isoforms of COX: COX-1 and COX-2. Aspirin inhibits both COX-1 and COX-2, leading to a decrease in prostaglandin production. This results in reduced inflammation, pain, and fever.Acetaminophen paracetamol is an analgesic and antipyretic drug that is not classified as an NSAID. Its exact mechanism of action is not completely understood, but it is believed to work primarily in the central nervous system. Acetaminophen is thought to inhibit the COX enzymes, similar to aspirin, but with a much weaker effect on COX-1 and COX-2 in peripheral tissues. This means that acetaminophen has a limited effect on inflammation but is still effective in reducing fever and relieving pain. Additionally, acetaminophen may also act on the endocannabinoid system and serotonergic pathways, which could contribute to its analgesic effects.In summary, aspirin and acetaminophen both reduce fever and relieve pain by inhibiting the production of prostaglandins through the inhibition of COX enzymes. However, aspirin has a more potent anti-inflammatory effect due to its stronger inhibition of COX-1 and COX-2 in peripheral tissues, while acetaminophen has a weaker effect on inflammation but still effectively reduces fever and pain through its actions in the central nervous system.